Suspected Taliban forces set off explosions as American military convoys rumbled down two roads in southern and eastern Afghanistan, injuring one Marine and damaging a vehicle, officials said Monday. The first attack occurred Friday in eastern Kunar province, said Maj. Mark McCann, an army spokesman. Some 40 rebels set off a roadside bomb, then opened fire on the convoy, injuring the Marine. His name was not disclosed, but McCann said his injuries were not life-threatening. On Sunday, rebels set off a bomb on a road in southern Kandahar province, damaging a Humvee but causing no casualties. Fighting between Taliban rebels and Afghan forces left at least four people dead last week, while 17 rebels were captured.